Music royalties are weird. Somebody that understood it way better than me explained it probably better than I will. From what I remember there is basically a performance, lyrics, and music portion. So when an artist covers a song they only get the performance part. The original artist gets the other two parts(assuming the music/lyrics weren’t written by somebody else). Since Al is redoing the lyrics he gets the performance and lyrics part but he’s still sticking money in the original artists pockets for the music portion. Most artists are plenty happy to have Al use one of their songs.